Anomalously large isotope effect in the glass transition of water
Anomalously large isotope effect in the glass transition of water
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DOI：
10.1073/pnas.1411620111
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发表时间：
2014-12-09
影响因子：
11.1
通讯作者：
Sokolov, Alexei P.
中科院分区：
文献类型：
--
作者：
Gainaru, Catalin;Agapov, Alexander L.;Sokolov, Alexei P.
我们在水的结构松弛和玻璃化转变温度T-g中发现了异常大的同位素效应。低密度无定形水和气相沉积无定形水的介电弛豫谱表明，H2O和D2O的T-g差为10+/-2K，与其他氢键液体形成鲜明对比，H/D交换使Tg增加通常不到1K。我们表明，水中大的同位素效应和低温下弛豫时间的异常变化可以用量子效应来解释。因此，我们的发现揭示了水独特的低温动力学，以及量子效应在其结构松弛中的可能作用，并可能在其他低分子液体的动力学中发挥作用。
We present the discovery of an unusually large isotope effect in the structural relaxation and the glass transition temperature T-g of water. Dielectric relaxation spectroscopy of low-density as well as of vapor-deposited amorphous water reveal T-g differences of 10 +/- 2 K between H2O and D2O, sharply contrasting with other hydrogen-bonded liquids for which H/D exchange increases Tg by typically less than 1 K. We show that the large isotope effect and the unusual variation of relaxation times in water at low temperatures can be explained in terms of quantum effects. Thus, our findings shed new light on water's peculiar low-temperature dynamics and the possible role of quantum effects in its structural relaxation, and possibly in dynamics of other low-molecular-weight liquids.